Nested classes

You can define a class within a class. If the nested class is declared as public, then you can create objects in the container class and return them to external code. Typically, however, you will want to declare a class that is used by the class and should be private. The following declares a public nested class:

    class outer 
    { 
    public: 
        class inner  
        { 
        public: 
            void f(); 
        }; 

        inner g() { return inner(); } 
    }; 

    void outer::inner::f() 
    { 
         // do something 
    }

Notice how the name of the nested class is prefixed with the name of the containing class.